title: Adsorption of methylene blue onto activated carbon produced from tea (Camellia sinensis L.) seed shells: kinetics, equilibrium, and thermodynamics studies.
abstract: Tea (Camellia sinensis L.) seed shells, the main byproduct of the manufacture of tea seed oil, were used as precursors for the preparation of tea activated carbon (TAC) in the present study. A high yield (44.1%) of TAC was obtained from tea seed shells via a one-step chemical method using ZnCl2 as an agent. The Brunauer-Emmett-Teller (BET) surface area and the total pore volumes of the obtained TAC were found to be 1530.67 mg(2)/g and 0.7826 cm(3)/g, respectively. The equilibrium adsorption results were complied with Langmuir isotherm model and its maximum monolayer adsorption capacity was 324.7 mg/g for methylene blue. Adsorption kinetics studies indicated that the pseudo-second-order model yielded the best fit for the kinetic data. An intraparticle diffusion model suggested that the intraparticle diffusion was not the only rate-controlling step. Thermodynamics studies revealed the spontaneous and exothermic nature of the sorption process. These results indicate that tea seed shells could be utilized as a renewable resource to develop activated carbon which is a potential adsorbent for methylene blue.
authors.affiliation: Department of Tea Science, Zhejiang University, Hangzhou 310058, China.
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Gao
authors.forename: Ye-Bo
authors.initials: YB
authors.lastname: Qin
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.forename: Dong-Dong
authors.initials: DD
authors.lastname: Cao
authors.forename: Ping
authors.initials: P
authors.lastname: Xu
authors.forename: Danielle
authors.initials: D
authors.lastname: Hochstetter
authors.forename: Yue-Fei
authors.initials: YF
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D028241:Camellia sinensis / Q000378:metabolism*; D002244:Carbon / Q000737:chemistry*; D002412:Cations; D002712:Chlorides / Q000737:chemistry; D004058:Diffusion; D004791:Enzyme Inhibitors / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D002412:Cations; D002712:Chlorides; D004791:Enzyme Inhibitors; D014874:Water Pollutants, Chemical; D017967:Zinc Compounds; D002244:Carbon; C016837:zinc chloride; D008751:Methylene Blue